The present invention relates to a multi-component proportioning system and a delivery system utilizing the proportioning system as well as a method of using the system. The delivery system is particularly useful in providing multi-component compositions to a multi-component dispenser which then can then deliver the components, for example, to a siphon or gravity-fed spray gun.
Various means have been suggested for proportioning and applying two or more components to a surface. In one such device, a main component and a secondary component are mixed together at an intermediate portion of a supply conduit to a coating spray gun. Check valves are provided upstream of a junction to prevent backflow from the junction and stop valves are provided in flow portions between the check valves and the junction to stop flow of material when the spray gun is shut off.
In another coating material supply device, coating materials reportedly are pumped by hydraulically controlled reciprocal pumps from a supply source at a constant flow rate by the pressure of a hydraulic fluid. In each of the hydraulically-powered reciprocal pumps, a coating material chamber having an inlet and exit and a hydraulic fluid chamber receiving the supply of the hydraulic fluid are formed adjacent with each other by way of a diaphragm so that the coating material in the coating material chamber is pumped out at a constant flow rate by the diaphragm.
A safety shut-down device for two-component sprayer systems is disclosed wherein the device is disposed in the compressed air line of a spray system particularly that which powers the spray component air motors and pumps. A pneumatically controlled main valve cuts off the compressed air to the air motors upon detection of a deficiency condition, i.e., lack of component pressure. Pressure is measured by pressure transducers which mechanically actuate deficiency valves.
In another multi-component spraying system, materials are pump-driven to a spraying means which includes a nozzle assembly which has a liquid nozzle for forming liquid, e.g., resin, into a fan-like film from a liquid orifice and a nozzle assembly for directing a flow of compressed air and catalyst at the film closely adjacent the orifice. Alternatively, compressed air impinges on a fan-like stream of resin and catalyst together prior to exiting the nozzle assembly as a mixture. The air pumps for each component being fed into the nozzle assembly may be individually controlled and the mixing unit for the materials may be carried, for example, on the belt of an operator, to reduce the weight of the hand-held spray gun.
In a device for simultaneously discharging a plurality of fluids. with or without mixing, the underside of a pistol grip handle of a spray gun or fuel nozzle is formed with a socket for a rotary insert which is connected to two or more supply conduits for flowable materials. The fluids to be discharged are presumed to be provided to the supply conduits by known means.
A multi-component system for applying a coating onto a substrate is provided whereby a plurality of separate components is supplied with at least one component being under pressure. Each component is transported to a common proportioning device powered by the pressure to provide a controlled volumetric ratio of the components. The components are homogeneously mixed to form a composition and the composition is sprayed or coated onto the surface of a substrate. The coating composition doubles in viscosity in centipoise at a temperature of 25xc2x0 C. within a time period of less than 45 minutes from the time of composition formation.
A two-component pressure feed system is disclosed wherein a first tank is provided within which a second tank is located and separated from the first tank by a membrane. One component is held in each tank. Pressurized air is fed to the containers and, via a regulator, a regulator pipe and through an aperture in the lid. Pressurized air feeds the fluid components via tubes to a spray gun, where the components combine to be sprayed.
An apparatus for applying multi-component coating compositions is also disclosed wherein at least two dosing devices, and air-assisted spray gun and a controlling device. Each dosing device has a supply container containing a component, a motor with a power controller, and a metering device. In each dosing device, the supply container is connected to the metering device which is connected the motor and to the spray gun. A connecting line between at least one metering device and the spray gun is fitted with a pressure transducer having means for measuring a decrease in pressure in the line and being connected to a control device connected to the motors to keep the pressure in the connecting line to a set value.
The present invention, in one aspect, provides a multi-component proportioning system for a multi-component coating composition comprising:
1) first, second, third and fourth pressurized air ports in a first valve assembly;
2) the second and third pressurized air ports being connected to a first air cylinder proximate the first and second terminal portions thereof,
3) the first and fourth ports being connected to an air cylinder associated with a second valve at the first and second terminal ends thereof,
4) first and second exhaust ports on the second valve and being connected to a second cylinder proximate the first and second terminal portions thereof and to quick exhaust valves;
5) a liquid pump assembly for each component, said liquid pump assembly comprising a piston which moves between a first and second chamber for the component and a piston rod attached to the piston extending beyond the pump assembly body;
6) a first and second trip plate adapted for contact with the piston rod associated with the liquid pump assembly for the first and second component;
7) an air pilot operator connected to the trip plate, the air pilot operator being adapted to contact a trip button in the first valve, the trip button determining air flow to the first, second, third and fourth air ports in the first valve; and
8) a spool valve assembly associated with each liquid pump assembly and having a component inlet port and a component outlet port, the inlet and outlet ports being connected to the chambers of the liquid pump assembly by passageways and a spool valve capable of directing incoming component entering from the inlet port to one chamber of the liquid pump assembly through a passageway and allowing outgoing component to exit from the other chamber of the liquid pump assembly through a passageway to the component outlet port, each spool valve assembly being further connected to the first air cylinder by connecting rods, the spool valve assemblies for the first and second components being connected to the first and second terminal portions of the first air cylinder, respectively;
such that when:
1) the first and second lines are pressurized with air, air flows from the first line to the second valve and through the first exhaust port and from the second line to the second terminal portion of the first cylinder, the first chambers of the liquid pump assemblies can fill with components through the spool valves attached thereto and components in the second chambers of the liquid pump assemblies can exit past the spool valve, while the piston with its rod moves across the liquid pump assembly and air exhausts through the third and fourth lines;
2) when the third and fourth lines are pressurized with air, air flows from the fourth line to the second valve and through the second exhaust port and from the third line to the first terminal portion of the first cylinder, the second chambers of the liquid pump assemblies fill with components through the spool valves attached thereto and components in the first chambers of the liquid pump assemblies exit past the spool valve and air exhausts through the first and second air ports;
3) when the first trip plate contacts the trip button in the first valve, the air pilot operator in the second valve, the piston and the spool valve simultaneously change direction, the piston and spool valve traveling in opposite directions, the pistons being operated by air pressure and the spool valves being mechanically operated.
Where more than two liquid pump assemblies and spool valve assemblies are required for the compositions containing more than two components, additional liquid pump assemblies and spool valve assemblies may be added by connecting the piston rod of the additional liquid pump assembly to the piston of the liquid pump assembly adjacent thereto and the spool valve attached to the air cylinder to the spool valve of the additional spool valve assembly by a rod or other means known to those skilled in the art with appropriate alignment being maintained.
The relative ratios of each component being fed out of the proportioning system is determined by the total volume of component capable of being held in each of the chambers of the liquid pump assemblies and is proportional thereto. Virtually any ratio of components can be achieved by using liquid pump assemblies of the appropriate volumetric capacities.
The multi-component proportioning system of the present invention provides many advantages over previously known systems. The system provides very accurate mix ratios due to the consistent, reproducible displacement of components from the liquid pump assemblies regardless of viscosity. Such accuracy eliminates improper mixing of components that can lead to reworking and lost time, materials, and profits.
The present invention, in another aspect, provides a multi-component delivery system utilizing the proportioning system of the invention The multi-component delivery system comprises:
1) a supply source for each component;
2) a multi-component proportioning system for a multi-component coating composition comprising:
a) first, second, third and fourth pressurized air ports in a first valve assembly;
b) the second and third pressurized air ports being connected to a first air cylinder proximate the first and second terminal portions thereof,
c) the first and fourth ports being connected to an air cylinder associated with a second valve at the first and second terminal ends thereof;
d) first and second exhaust ports on the second valve and being connected to a second cylinder proximate the first and second terminal portions thereof and to quick exhaust valves;
e) a liquid pump assembly for each component, said liquid pump assembly comprising a piston which moves between a first and second chamber for the component and a piston rod attached to the piston extending beyond the pump assembly body;
f) a first and second trip plate adapted for contact with the piston rod associated with the liquid pump assembly for the first and second component;
g) an air pilot operator connected to the trip plate, the air pilot operator being adapted to contact a trip button in the first valve, the trip button determining air flow to the first, second, third and fourth air ports in the first valve; and
h) a spool valve assembly associated with each liquid pump assembly and having a component inlet port and a component outlet port, the inlet and outlet ports being connected to the chambers of the liquid pump assembly by passageways and a spool valve capable of directing incoming component entering from the inlet port to one chamber of the liquid pump assembly through a passageway and allowing outgoing component to exit from the other chamber of the liquid pump assembly through a passageway to the component outlet port, each spool valve assembly being further connected to the first air cylinder by connecting rods, the spool valve assemblies for the first and second components being connected to the first and second terminal portions of the first air cylinder, respectively,
such that when:
a) the first and second lines are pressurized with air, air flows from the first line to the second valve and through the first exhaust port and from the second line to the second terminal portion of the first cylinder, the first chambers of the liquid pump assemblies can fill with components through the spool valves attached thereto and components in the second chambers of the liquid pump assemblies can exit past the spool valve, while the piston with its rod moves across the liquid pump assembly and air exhausts through the third and fourth lines;
b) when the third and fourth lines are pressurized with air, air flows from the fourth line to the second valve and through the second exhaust port and from the third line to the first terminal portion of the first cylinder, the second chambers of the liquid pump assemblies fill with components through the spool valves attached thereto and components in the first chambers of the liquid pump assemblies exit past the spool valve and air exhausts through the first and second air ports;
c) when the first trip plate contacts the trip button in the first valve, the air pilot operator in the second valve, the piston and the spool valve simultaneously change direction, the piston and spool valve traveling in opposite directions, the pistons being operated by air pressure and the spool valves being mechanically operated.
3) means for connecting each supply source to the component inlet port on a spool valve assembly,
4) means for connecting each component outlet port to a dispenser adapted to individually deliver the components to a coating device.
A flushing system may also be provided by adding a flush assembly to discontinue supply of the components and supply the inlets of each spool assembly with an appropriate cleaning solution.
The combination of the spool valve assembly, liquid pump assembly, mechanical and air pressure control and the quick exhaust valve virtually eliminate pulsing at the spray gun. With this delivery system, components can be fed directly from shipping containers and reactive activators can be fed by venting the container through a desiccant filter which maintains a dry atmosphere above moisture sensitive activators. This system requires no pressurized feed tanks, pumps or circulation systems to feed the components which reduces equipment needs and costs. The system further saves labor necessary in mixing components, cleaning mixing containers and handling waste over many known systems.
The present invention, in a further aspect, provides a method of using a multi-component proportioning system for a multi-component coating composition comprising the steps of:
1) providing an air pilot valve assembly comprising first and second 4-way, 5-port valves, each valve having a pressurized air inlet, the first valve having first and second Y-connectors and an air pilot operator adapted to trip a trip button within the first valve to direct air flow to the Y-connectors and the second valve having first and second air inlet ports and first and second primary exhaust ports,
2) providing a liquid pump assembly for each of at least two components, said liquid pump assembly comprising a piston which moves between a first and second chamber for the component and a piston rod attached to the piston extending beyond the pump assembly body, each of the liquid pump assembly piston rods for the first and second components being adapted to contact a trip plate, and the trip plate being connected to a piston rod adapted to traverse a second cylinder;
3) providing a spool valve assembly associated with each liquid pump assembly and having a component inlet port and a component outlet port, the inlet and outlet ports being connected to the chambers of the liquid pump assembly by passageways and a spool valve capable of directing incoming component entering from the inlet port to one chamber of the liquid pump assembly through a passageway and allowing outgoing component to exit from the other chamber of the liquid pump assembly through a passageway to the component outlet port, each spool valve assembly being further connected to a first air cylinder by connecting rods, the spool valve assemblies for the first and second components being connected to the first and second terminal portions of the first air cylinder, respectively;
4) providing pressurized air to the air inlet of the first 4-way, 5-port valve and allowing the air to exit the first valve through the first Y-connector;
5) allowing air flowing through a first port of the first Y-connector to enter into a terminal portion of a first air pilot operator portion;
6) allowing air flowing through a second port on the first Y-connector to flow into the first air cylinder and to cause a piston rod and a piston located within the first air cylinder and aligned with the central axis thereof and the spool valves to travel in a first direction;
7) allowing air to flow from the second exhaust valve of the air pilot valve assembly to an exhaust line connected to a second air cylinder and a first quick exhaust valve causing pistons and piston rods of the liquid pump assembly, the trip plate, the piston rod in the second air cylinder and the air pilot operator to travel in a direction opposite to that of the spool valves;
8) providing a component for each liquid pump assembly and associated spool valve assembly;
9) permitting the liquid pump assembly for each component to draw the component into the first chamber of the liquid pump assembly through the component inlet port of the spool valve assembly associated therewith and causing component contained in the second chamber of the liquid pump assembly to exit through the component outlet port of the spool valve assembly associated therewith;
10) allowing the spool valve and associated piston rods to continue travel in a first direction and the piston in the liquid pump assembly, the trip plate and the air pilot operator to continue travel in the opposite direction until sufficient travel has occurred that the air pilot operator contacts the trip button in first valve of the air operator assembly system causing air to flow into the second Y-connector;
11) allowing air flowing through a first port of the second Y-connector to enter into a terminal portion of a second air pilot operator portion;
12) allowing air flowing through a second port on the second Y-connector to flow into the first air cylinder and to cause the piston rod and a piston located within the cylinder and the spool valves reverse direction and to travel in a second direction opposite to the first direction;
13) allowing air to flow simultaneously with that of the air flowing through the port on the second Y-connector from the first exhaust valve of the air pilot valve assembly to an exhaust line connected to the second air cylinder and the second quick exhaust valve causing pistons and piston rods of the liquid pump assembly, the trip plate, the piston rod in the second air cylinder and the air pilot operator to reverse direction and travel in a direction opposite to that previously traveled;
14) permitting the liquid pump assembly for each component to draw the component into the second chamber of the liquid pump assembly through the component inlet port of the spool valve assembly associated therewith and causing component contained in the first chamber of the liquid pump assembly to exit through the component outlet port of the spool valve assembly associated therewith,
15) allowing the spool valve and associated piston rods to continue travel in the second direction and the piston in the liquid pump assembly, the trip plate and the air pilot operator to continue travel in the direction opposite to that previously traveled until sufficient travel has occurred that the air pilot operator contacts the trip button in first valve of the air operator assembly system causing air to flow into the first Y-connector; and
16) repeating steps 5 through 15 until stoppage of delivery of the components is desired.